Valve device.



*UNiTED STATES PATENT onnicii.

JOHN stomen, or CLEVELAND, aonnivivnsisune, ,rnANsvAnn vaLvE 1 nevica.

speeincatinef ieaersratenf. Patentedjune 14,1910,4

Applieationnled October-19, 1908i Serial Ne.,458,424.i'

sanita whomfit may hoffmann.l

V` J F-'Beitknownthat-I, 'JOHN Snoeien,- engi-l neer, a subject of the King of GreatBritain,

residing at Geldenhuis Estate and Gold Mining Company, Cleveland, Johannesburg,

I Colony of the Transvaal, have invented cer- 'tain new and useful Improvements iii Valve- Y Devices Afor DirecteActing Engines, of which the following is -a specification. v .Direct acting engines for rock drilling and other purposes areknown in which the piston, onlapproach-ing either end Yof its stroke, lii'r'stcloses anexhaust .port in -the cylinder `Jvall and then compresses the remaining air). between itself and thecylinder cover.

Such compressed air is forced up the induction ort for the cylinder end in question, *l and orcesa distributing valvefrom oif the for the other end of the cylin vnamed end having already been exhausted through a cylinder wall port. Live air thus rives the piston on its return stroke; upon is reversed .I scribed.

. creased; in which'thevalve varied as vmay be necessar by w `ich the startingmoutho-f said port and causes itto close the mout-h of the similar inductionport provided er, such'last large area available -both for moving the' valve and passing air to the cylinder, so that the'travel of the valve may be very short, and the eiicieney of the machine thereby intravel may be for'the reasons hereafter stated; and of the machine in any position is assured.

A rock drilling engine embodying the iin'- proved valve is shown in the accompanyingl drawings, in which- Figure engine, Fig. II a plan thereof, Fig. III is an enlarged elevation of the valve detached, and

Fig. \IV' is a view of the: left hand end thereof, and Fig. V is a section on the plane Aj-A Fig. III looking toward the left.

1 represents the cylinder with the piston 2 worln'ng therein.

3- and 4 are the induction ports to the frontand rear end s lrespectively of the cy'linder.

yworking ,fluid (hereinafterA referred to as I is a longitudinal section of the ythe piston forward.

5 6, are exhaust por-ts` leading-l from the cylinder bore directly to the atmosphere.

Positioned longitudinally upon the cylinchamber Ik8 to which live air is supplied through inlet 9,V and the terminals of the inf duction ports 3 and 4 which are separated froinchamber 8 by the walls '10 and 11. The

vinduction port 3 from the front'of the cylinderfis carried `to the rear of the valve chest, and the induction port 4 to the front thereof.

The valve 12 is of the sldingtype, formed with fiat or substantially flat end faces. 13

der is the valve chest 7 whichincludes the and. 14 coperating with corresponding faces onthe seats 15 and 16,. so as to provide a large lopening inproportion to the travel. Said seats are apertured for the passage of air through them; ,being in theA example shown, perforated 'by annular series of holes 17.r4

' In the present case 'the valve is bored axially and slides upon a spindle 18 pro- Jecting from the valve seat 15. The second seat 16 is formed with an Jextension `piece 19 upon which is formed a collar 20 somewhat larger in diameter than the seat proper.

Internally the seat is threaded uto screw upon tlieJspindle 18'; and the collar 20 has cut upon it an external thread equal in pitch y to the spindle thread. lBeyond the collar the extension is shaped to form a grip 21 forl a wrench, as is also-.the end 22 of the YV'spindle 18.

lock nut working lupon' the spin- 23 is a dle 18.

The valve having spindle 18 and the seat 16 screwed up thereon to the requisite distance, the lock nut 23 is screwed home, thus securing the two` seats against relative movement. The strucbeen placed upon -the ture is then inserted through a tapped hole in wall 2e of the valve chest, into which the collar 2O is engaged. Seat 15 is formed r with a reduced end which when the seat is in position passes linto a circular orifice in' wall 11, while theshoulder formed by such reduced end abuts against said wall. Seat 16 enters and lls theorilice in wall 10.

In operation, the parts being..positioned as seen in Fig. I,- live air passesfroni chainber 8 to the back ofthe cylinder and drives The air in front of the piston is at rst exhausted through ports 5 and 6, but after the latter is covered, the remaining air is compressed, forced up port tudinally lateral tilti'ng of thei machine having no 3, and throws the valve over. Live air is thus admitted to the'front of the piston and the air behind it having already been 'exhausted through port 5, the piston returns; and by Acompresslng the air in the rear of the cylinder, again reverses the valve.

. The exhaust ports 5 and 6 are placed nearer to the front than to the rear endof the cylinder, in order to afford a comparatively free working stroke and substantial cushioning upon thereturn stroke. By arranging 4the valve and .induction ports in lthe manner described, the valve will always assume the correct position'for starting the machine should the latter be inclined longivfor drilling up or down holes,

effect. V v

A short and rapid valve stroke is essential to the vfullest eiiiciencyof an engine of the class in question. The throw over should in fact be as nearly as possible instantaneous, since so long as the valve is in motion both .induction ports are taking air. With a comparatively slowly movin valve, such as the ball valve? hitherto use in engines of this class, air continues to pass to an undue extent to the 'advancing side of the piston and is unable to escape before closure of the exhaust port, so that the piston'is choked. In fact an vapparently slight reduction of the speedl of the valve may cause the motion of v. the piston to degenerate into a mere oscillation over the exhaust port-s. The travel of the valve is therefore in practice reduced to the smallest limit consistent with the avoidance of substantial wire drawing of the air, and to obtain the best eiiiciency'with any articular machine thev valve travel should bel adjusted in accordance with the pressure of the air. Thus upon the pressure being substantially altered at any time, or the valve and seats having become worn, the distance between the seats would be adjustid accordingly, a less valve opening-being` required as the pressure is raised, and vice versa. Such adjustment may readily be made with the device described, by slacking the lock nut 23, holding spindle 18 by means of a Spanner applied to its polygonal end 22, screwing seat 16 in or out as the case may be by means 'of a second Spanner applied to its polygonal partv 21', and finally re-locking the parts by means of nut 23.

The improved valve device described, when properly set,-will enable very high piston speeds to be attained; while of course the small momentum attained. by t-he valve minimizes wear. It may also be noted that the absence-of aseparate air supply for operating the valve permits a material economy of compressed air to be effected.

What I claim, and desire to secure by Letters Patent is 1. In an engine of the class specified, in

combination the-,cylinder 1, piston 2, induct1on ports 3 and 4 to the cylinder ends, the valveA chest 7 comprising the central feed chamber 8 and the ,terminals of the induction ports, the valve 12 having fiatend' faces 13 and 14.-, and the detachable Valve seating comprising the perforated seat 15 carrying aV threaded spindle 18 upon which the valve is loosely mounted, and the seat16, said valve seatingbeing held in the walls of the' vvalve chest by means of a threaded collar 20 upon the seating 16, lsubstantially as described. l v

2. The combination with a working cylinf der havingadmission'and exhaust ports, of a valve chest having a centrally arranged supply chamber for the motive fluid, a ing spindle arranged parallel with 'the axis of the cylinder and extending thrugh the supply chamber, a valve mounted to slide thereon having flat end faces surrounding the s indle, and valve seats surrounding the spin le having flat faces corresponding with the faces of the valve andapertured to permit the passage of the motive riuidg'from Y the supply chamber to the admission ports.

3. The combination of a cylinder provided with exhaust ports, a valve chest having :i centrally arranged supply chamber for tile motive iiuid, ports connecting the respective ends vof the cylinder with the valve chest and terminating in the valve seats, a valve in the` guidvalve chest adapted to be moved by compression of the iuid in the cylinder ends alternately to cover said lvalve seats and means for varying the travel of the valve to accommodate variations of pressure. j

. 4. The combination with a working cylinder having admission and exhaust ports, of a valve chest having a centrally arranged sup'` ply chamber for the motive fluid va spindle arranged parallel with the axis o l the cylinder extending through the supply chamber, an apertured valve seat surreunding the spindle at one end of the supply chamber,

a sleeve adjustable on the spindle and provided with an apertured valvev seat on the opposite side of the valve ,chamber, means for adjusting the sleeve on theispindle to move onevalve seat toward 'endif' fromu the other to alter thel travel 'of the vflve, and a valve mounted to slide on the spindle between the valve seats.

'5. The combination with a working cylinder andV its working pistonof a valve chesthaving a centrally arranged supply chamber for the motive fluid, a passage for motive fluid leading from the rear end of the valve chamber to the front portion of the cylinder, a passa ge'for conveying the motive fluid leading from the frontend of the valve chest to the rear portion of the working cylinder,

* ppost amis 'of the valve chamber,` ab sion passe the ontlpoton'of l() plston reoiprocatingn the Workingcylinthovalve chest der-which during' lts' forward 'strokqcomltrolling valve. v pressesthe motive-Huid through. the admis- In testimony whereo i I ax my signature sion passage to the'lgear end of the valve in the presence ofitwo witnesses. chest ami thus moves. the valve'to admit. the l JOHN' SLORACH.: motveuid to the `iront portion of the cyl! vvitavmasses: l inder and which on the rear strokeJ oom- Jh DENNDIG, presses the motive'ui'' through the admis WESLEY E. JOHN, v

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